1. Field of the Invention.
The present invention relates to power driven socket-type ratchet wrenches
2. Description of the Prior Art.
The number of ratchets that have been advanced over the years is legion. The need for dependable and convenient operation, as well as compact size for moving into small spaces has been desired. There have been well known power driven ratchet wrenches such as the pneumatic wrench made by Universal Tool of 18125 Ammi Trail, Houston, Tex. 77060. The ratchet head for the tool is driven by a small crank that has a pin which drives the ratcheting mechanism. However, the ratchet itself is a conventional enclosed ratchet, and while reversible, it does not include several desired features, such as the ability to operate on long studs or bolts.
Representative of socket wrenches that have through openings in the socket is the device shown in U.S. Pat. No. 4,259,883. It has an interchangeable socket member nested in an outer ring, and drive teeth on the exterior of the ring. A ratchet pawl that will engage these teeth for driving the socket with the head and handle is provided.
The socket is retained in place within the drive ring with a wire spring member which can be released for dropping the socket out and replacing it with another. The through opening in the socket permits a stud to pass through the socket itself when the socket is being operated.
The socket has substantial vertical height, and in view of the retaining mechanism, the necessary vertical or axial height of the wrench and socket is increased substantially. Additionally, the mechanism for releasing the socket from the wrench has two members that are moved for deflecting the spring for removal of the socket. Because the socket itself is driven an outer ring or fitting additional mechanism is required for operation.
An early form of a type of socket that had a center opening in the socket itself and was used in a ratchet wrench is shown in U.S. Pat. No. 603,377, patented May 3, 1898 and issued to Fitch. This unit has a spring retainer that frictionally retains the socket in place, and uses, again, an outer drive member that ratchets. The outer drive member has an inner periphery that has, in this form, a square cross section for driving an insertable socket.
Another early patent, U.S. Pat. No. 635,207 issued to Tilton on Oct. 17, 1899, shows a socket wrench that has a center opening, but which uses a split handle and a very elementary socket drive. This socket, however, has large teeth on the outer surface of the socket. The socket is not easily removable, but is more or less permanently retained in place with the handle. The handle is split and can be separated for changing sockets. One of the features is that the socket has two different size openings, accessible from the opposite ends of the socket, for use with different size nuts.
U.S. Pat. No. 1,292,281 issued to Esterhay on Jan. 21, 1919, shows a ratchet wrench that has a handle, with a pawl that drives an outer ratcheting ring member, which is permanently mounted in the handle. The ring has exterior ratchet teeth thereon for driving, with a square internal opening, and a matching cross section socket that fits into the opening for replacement. The socket is mated in the drive ring with a key and slot arrangement.
U.S. Pat. No. 2,725,771 issued Dec. 5, 1955, to Arnold shows a power driven ratchet wrench having external teeth on the socket used for driving the socket, but utilizing a complex connecting rod arrangement for reciprocating the socket.
U.S. Pat. No. 3,529,498, issued Sept. 22, 1970 to Northcut also shows an eccentric drive ratchet wrench operating with a power motor, and having a ball type socket for driving an outer reciprocating element that operates to drive a ratchet pin that fits onto a conventional socket.
Other pneumatic or power wrenches are shown in U.S. Pat. No. 4,346,630, issued Aug. 31, 1982, to Hanson. This patent shows another type of power driven ratchet wrench utilizing an ordinary square socket drive and holder, and a reciprocating pawl that rotates with the portion driving the socket, and engages internal fixed gear teeth.
U.S. Pat. No. 3,077,801, issued Feb. 19, 1963 to Rostad shows an open end ratchet wrench that has a type of socket that has teeth on the outside, but an outer end flange that rests against a portion of the wrench proper, and which holds the socket in place. This is a hand driven ratchet wrench having an open slot at one side, so that it can be placed over a bolt or the like.
U.S. Pat. No. 1,451,498, issued to Faitz on Apr. 10, 1923, shows a ratchet wrench which has a drive pawl and drive ring mounted in the handle and a replaceable socket that fits within the ring. The socket has a through opening for receiving a stud or bolt. In this device, the socket has an outer cross section that fits into an opening in the ratchet drive ring for driving. This increases the size of the head of the socket wrench and makes it less accessible for small clearances.
U.S. Pat. No. 1,769,070 issued to Nowosielski on July 1, 1930, shows a ratchet wrench having a socket wheel that has teeth on the outer surface thereof and a pawl mounted directly in the handle, which reduces the height of the wrench in direction along the axis of rotation. The socket is retained with balls fitting into a groove around the periphery of the socket, and release of the socket for changing is more difficult with such arrangement.
U.S. Pat. No. 2,358,362 issued to Taylor on Sept. 19, 1944, also shows a ratchet wrench with a socket member that has teeth directly on the outside of the socket and which has a head member that forms a type of a "hook" ratchet. The head does not have a socket encircling ring, but rather the socket fits into a receptacle that is open on one side and the socket is retained in place with finger-like springs.
U.S. Pat. No. 2,536,172 issued to Halperin on Jan. 2, 1951, shows a ratchet wrench for turnbuckles that has a ratchet wheel that splits open and has a pin for driving the turnbuckle. The opening action is made so that the wrench can be placed around a continuous rod and operated to tighten or loosen a nut.
U.S. Pat. No. 3,299,750 issued to Campanile et al. on Jan. 24, 1967, shows a replaceable socket member that has a neck section with ratchet teeth on the socket, which has a single retaining ring that can be used for releasing the socket and replacing it with another. This socket also ratchets upon operation of the handle, and has a through opening for permitting a stud to pass completely through the socket so that the length of the stud or bolt being operated does not cause interference.
U.S. Pat. No. 3,732,756 issued to Thomasian on May 15, 1973, shows a socket having external teeth driven from the pawls of a ratchet wrench. The socket has different shaped openings at its opposite ends.
A ratchet lever is shown in U.S. Pat. No. 4,308,768 issued to Wagner on Jan. 5, 1982 and illustrates a type of socket to be driven which has a head ring for receiving an interchangeable locking ring. It does show a socket member that has a through opening as well.
U.S. Pat. No. 4,328,720 issued to Shiel on May 11, 1982, shows another type of sprocket that has a through opening, and which has means for retaining it in place and which has ratchet teeth on the outside. However, the unit is an insert socket arrangement, so that the ratchet drive is not to teeth on the socket itself.
Additional art of general interest is shown in U.S. Pat. No. 4,095,494 issued to Castoe on June 20, 1978, which shows a gear operated ratchet wrench that has a swing open frame for putting it onto a continuous member for tightening or loosening a portion of the member. U.S. Pat. No. 613,153 issued to Kennelly on Oct. 25, 1898, shows a outer drive housing that has teeth on the outside for driving the unit as a ratchet.
U.S. Pat. No. 3,602,071 shows a gear driven "open end" wrench. The wrench gear is driven by an air motor, but does not ratchet.
U.S. Pat. No. 4,475,420 issued to Atkinson et al on Oct. 9, 1984 is a wrench apparatus that shows a gear drive, and is merely of general interest. Additionally, there are a side number of conventional ratchet wrenches using sockets that do not have openings through the center.